The protection of device and data integrity has become essential as common interactions are increasingly performed via electronic communication. For example, users may execute data and financial transactions, business-related transactions, etc. utilizing electronic communication. In these interactions confidential information may be transmitted to other devices in a network such as a global area network (GAN), a wide area network (WAN) like the Internet, a local area network (LAN). Confidential information may also be received from other devices in a network and stored on a user's device. As a result, devices may comprise confidential information for the user of the device and possibly other users. Over time the confidential information may grow to include personal identification data, medical/health data, financial data, residence data, account numbers, passwords, professional information such as registration/license data, office location, contact data, client data, etc. Certain attackers having possibly malicious intent may desire to obtain this type of information to utilize for their own benefit, sell to others, etc.
The increasing threat to both devices and data has driven continual security improvement. However, as new protections emerge attackers devise creative ways to overcome them. Designers attempt to combat these new breaches with even more impregnable defenses. For example, some devices may include processing circuitry that may operate in a secure mode for brief periods of time. The secure mode may be privileged so that only the processing circuitry may operate, and thus, all other activity in the device is suspended. To help ensure that the device may seamlessly return to a normal mode of operation, the “state” of a microprocessor in the processing circuitry may be saved upon entering the secure mode, and may be restored just prior to returning to the normal mode. The state may include, for example, the values of registers, variables, etc. used by the processing circuitry, pointers to memory locations, etc. While the state may be stored in a secured memory location, it has been determined recently that an attacker's ability to flip even one bit in the state could change the operation of the processing circuitry when the state is restored. The bit could put the processing circuitry into a vulnerable mode that may allow an attacker to edit, delete or insert data, or to otherwise manipulate the processing circuitry to obtain remote control over some of, or the entirety of, the device, access valuable information stored in the device, etc.
Although the following Detailed Description will proceed with reference being made to illustrative embodiments, many alternatives, modifications and variations thereof will be apparent to those skilled in the art.